Impact of Algae Blooms on the Coastal Zone of the Curonian Lagoon of the Baltic Sea

The Curonian Lagoon (a lagoonal ecosystem with predominantly freshwater conditions) is a hypertrophic reservoir. Throughout the entire water area, including the coastal zone, which is of important fishery and recreational importance, phytoplankton blooms are observed annually. Monthly data obtained in 2014-2015 on chlorophyll a and hydrochemical parameters have been analyzed. The seasonal dynamics of chlorophyll a (phytoplankton abundance) throughout the Russian waters of the Curonian Lagoon and the influence of phytoplankton blooms on hydrochemical and microbiological indicators in the coastal zone near the Curonian Spit National Park (UNESCO World Heritage List) are analyzed. During the period of intensive development of cyanobacteria ("hyperbloom"), it's spatial distribution in Russian waters, assessed by chlorophyll, is preconditioned by the wind regime, which causes local accumulation in certain areas. The accumulation of phytoplankton in the coastal zone (including the area along the Curonian Spit National Park) in summer and autumn may form harmful hydrochemical and microbiological conditions, corresponding to hypertrophic and hypersaprobic levels and multiple excesses of the maximum permissible concentration (BOD5 and ammonia nitrogen; anaerobic conditions).